Applicable to D3D11 only, although the flag is general enough that
other backends could use it if it made sense for them.
This allows Qt Quick to state that warnings about QRhi::create()
failures that lead to retrying with a different set of flags
(PreferSoftwareRenderer to get to use the WARP software rasterizer)
should be suppressed and turned to regular categorized debug prints.
Other users, e.g. an application directly working with QRhi may not
want this. A create() failure must be complemented by an unconditional
qWarning since normally that is pretty serious error. Hence the opt-in
flag.
Task-number: QTBUG-117926
Change-Id: I808bd1670b631e2068b566ab08589e1783f62ca5
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
92167f0119